1. Field of the Invention
The invention relates to carpeted staircases. More particularly, the invention relates to a three dimensional pad which is placed on stringer portions of a staircase prior to carpeting the staircase. After the staircase is carpeted, the stringer portions of the staircase exhibit a modern billowing appearance.
2. State of the Art
A staircase 10 such as the one shown in FIG. 1 is composed of a number of treads 12 which are interspaced by a corresponding number of risers 14. On either side of the treads 12 and risers 14 is a stringer 16, 18. The treads 12 and risers 14 are typically arranged at right angles to each other as shown, but those skilled in the art will realize that the angle between treads and risers may vary from 90.degree.. In general, adjacent treads and risers have surfaces which lie in intersecting planes and the stringers have surfaces which lie in a plane which intersects the planes of both the treads and the risers. As seen in FIG. 1, one stringer 16 (an upper stringer) is located above the treads 12 and the other stringer 18 (a lower stringer) is located below the treads 12. However, those skilled in the art will appreciate that both stringers may be located either above or below the treads depending on various architectural considerations. The stringers 16, 18 have a generally toothed profile. In a staircase having risers and treads which are at right angles to each other, the stringers have a profile which resembles a number of right triangles joined in a line at their hypotenuses. Each right angle in the stringer corresponds to the intersection of a corresponding tread and riser. In some staircases, the treads extend slightly beyond the risers to form a lip. The tread lip may be located forward of the riser as indicated by 12a in FIG. 1 or rearward of the riser as indicated by 12b, or both. When the staircase has tread lips, the stringers will often be provided with corresponding notches, e.g. 16a, 18a for each lip the stringer intersects.
It is, of course, well known to apply carpeting to a staircase. Traditionally, a carpet runner is applied to a central portion of the treads and risers leaving the stringers and side portions of the treads and risers uncarpeted. In modern wall-to-wall carpeting, it is known to apply carpeting across the complete width of the risers and treads. In some cases, the stringers are also carpeted by cutting pieces of carpeting to conform to the stringers. Whereas the traditional carpeting of staircases left the treads and risers well defined, modern wall-to-wall techniques tend to obscure the treads and risers. Staircases carpeted with modern wall-to-wall techniques have an aesthetically bland two-dimensional appearance and can also be hazardous insofar as the treads and risers are so obscured to the eye.